I also had some .mobi names , but i let them drop
It seems they still be a good marketing name ? due to the fact the net is getting more and more mobile these days , but i would suggest more for marketing than any other reason
Most people seem very down on this extension , which could mean there are good keywords still up for sale cheap.
It seems because any .extension can be used as a mobile extension the original idea behind it is now redundent ?
and then there is the whole .tel situation as well